﻿using AnyCAD.Forms;
using AnyCAD.Foundation;
using System;

namespace AnyCAD.Demo.Graphics
{
    class Graphics_ShaderBlackHole : TestCase
    {
		String shaderName = "blackHole_shader";
		void CreateShader()
		{
			if (ShaderTemplateManager.Instance().IsExist(shaderName))
				return;
            
			ShaderTemplateManager.Instance().Create(shaderName,
            @"
			varying vec2 vUv;
			void main()	{
				vUv = uv;
				gl_Position = vec4( position, 1.0 );
			}                    
            ",
            @"
			varying vec2 vUv;

			uniform float time;

			void main()	{

				vec2 p = - 1.0 + 2.0 * vUv;
				float a = time * 40.0;
				float d, e, f, g = 1.0 / 40.0 ,h ,i ,r ,q;

				e = 400.0 * ( p.x * 0.5 + 0.5 );
				f = 400.0 * ( p.y * 0.5 + 0.5 );
				i = 200.0 + sin( e * g + a / 150.0 ) * 20.0;
				d = 200.0 + cos( f * g / 2.0 ) * 18.0 + cos( e * g ) * 7.0;
				r = sqrt( pow( abs( i - e ), 2.0 ) + pow( abs( d - f ), 2.0 ) );
				q = f / r;
				e = ( r * cos( q ) ) - a / 2.0;
				f = ( r * sin( q ) ) - a / 2.0;
				d = sin( e * g ) * 176.0 + sin( e * g ) * 164.0 + r;
				h = ( ( f + d ) + a / 2.0 ) * g;
				i = cos( h + r * p.x / 1.3 ) * ( e + e + a ) + cos( q * g * 6.0 ) * ( r + h / 3.0 );
				h = sin( f * g ) * 144.0 - sin( e * g ) * 212.0 * p.x;
				h = ( h + ( f - e ) * q + sin( r - ( a + h ) / 7.0 ) * 10.0 + i / 4.0 ) * g;
				i += cos( h * 2.3 * sin( a / 350.0 - q ) ) * 184.0 * sin( q - ( r * 4.3 + a / 12.0 ) * g ) + tan( r * g + h ) * 184.0 * cos( r * g + h );
				i = mod( i / 5.6, 256.0 ) / 64.0;
				if ( i < 0.0 ) i += 4.0;
				if ( i >= 2.0 ) i = 4.0 - i;
				d = r / 350.0;
				d += sin( d * d * 8.0 ) * 0.52;
				f = ( sin( a * g ) + 1.0 ) / 2.0;
				gl_FragColor = vec4( vec3( f * i / 1.6, i / 2.0 + d / 13.0, i ) * d * p.x + vec3( i / 1.3 + d / 8.0, i / 2.0 + d / 18.0, i ) * d * ( 1.0 - p.x ), 1.0 );

			}

			",
            @"
			float time 1.0;
			");
		}

		MaterialInstance mMaterial;
        public override void Run(RenderControl render)
        {
			CreateShader();

			mMaterial = MaterialManager.Instance().FindInstance("blackHole_instance");
			if(mMaterial == null)
			{
				var template = MaterialManager.Instance().CreateTemplateByName("blackHole_shader_template", shaderName);
				mMaterial = MaterialManager.Instance().Create("blackHole_instance", template);
			}

			var plane = GeometryBuilder.CreatePlane(2, 2);
			var node = new PrimitiveSceneNode(plane, mMaterial);

			node.SetPickable(false);

			render.ShowSceneNode(node);
        }

        public override void Animation(RenderControl render, float time)
        {
			if (mMaterial == null)
				return;

			mMaterial.SetUniform("time", time);

			render.RequestDraw();

		}
    }
}
